Increase DetailsPerStream IntervalSetVec size
Increase DetailsPerStream IntervalSetVec size

Summary: As in title.

Reviewed By: bschlinker

Differential Revision: D36151208

fbshipit-source-id: eff57cf51156db0f849e64133b75d7acf8ac9ca3

facebookincubator/mvfst,facebookincubator/mvfst,facebookincubator/mvfst,facebookincubator/mvfst,facebookincubator/mvfst